Astros second baseman Jose Altuve runs for first while Matt Downs heads home with the winning run as Altuve's bases-loaded grounder went through the legs of Wilson Valdez to cap a two-out rally in the bottom of the ninth inning for a 2-1 win over the Reds. less

Sept. 1: Astros 2, Reds 1

Astros second baseman Jose Altuve runs for first while Matt Downs heads home with the winning run as Altuve's bases-loaded grounder went through the legs of Wilson Valdez to cap a ... more

Photo: Smiley N. Pool / Chronicle

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Houston Astros pinch hitter Matt Downs celebrates as he doubles off Cincinnati Reds relief pitcher Sean Marshall to start a two-out rally in the bottom of the ninth inning.

Houston Astros pinch hitter Matt Downs celebrates as he doubles off Cincinnati Reds relief pitcher Sean Marshall to start a two-out rally in the bottom of the ninth inning.

Houston Astros second baseman Jose Altuve is mobbed by teammates after the win.

Houston Astros second baseman Jose Altuve is mobbed by teammates after the win.

Photo: Smiley N. Pool / Houston Chronicle

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Aug. 31: Reds 9, Astros 3

Houston Astros right fielder Fernando Martinez, bumps fists with Astros third base coach Dave Clark after hitting a solo home run off Cincinnati Reds starting pitcher Mike Leake during the fourth inning. less

Aug. 31: Reds 9, Astros 3

Houston Astros right fielder Fernando Martinez, bumps fists with Astros third base coach Dave Clark after hitting a solo home run off Cincinnati Reds starting pitcher Mike Leake during ... more

Cincinnati Reds right fielder Jay Bruce is met at the plat by teammates Ryan Ludwick, left, and Chris Heisey after hitting a 3-run home run off Houston Astros starter Fernando Abad during the fifth inning.

Cincinnati Reds right fielder Jay Bruce is met at the plat by teammates Ryan Ludwick, left, and Chris Heisey after hitting a 3-run home run off Houston Astros starter Fernando Abad during the fifth inning.

August came to a merciful end Friday night in typical fashion for the woebegone Astros: a shorter bench, owing to their latest hit of misfortune in a star-crossed season, and a longer losing streak.

The loss, the Astros’ sixth in a row and 22nd in 27 games during a month that also included a managerial change and a back-and-forth exchange program with the Class AAA team in Oklahoma City, came 9-3 to the Reds before 15,287 at Minute Maid Park.

Jay Bruce, the former Beaumont West Brook star, keyed the four-run fifth inning for the Reds with a three-run homer off Fernando Abad, who entered the inning with the game tied.

The misfortune was the loss, potentially for the season, of infielder Marwin Gonzalez, who was diagnosed with a torn ligament in his left ankle after jamming his foot Thursday night.

Reinforcements needed

Interim manager Tony DeFrancesco initially said Gonzalez would not return this season, but team officials later clarified that he may be back.

“We have Sept. 1 coming up, and I’m sure there will be roster moves,” DeFrancesco said. “We should get some help on the way.”

Help will come at a good time for a team that continues to see glimmers of hope from recent additions like third baseman Matt Dominguez, who hit his first big league homer, but struggles to hold leads and is in need of a major bullpen restructuring.

The Astros never led Friday, but at least were on even footing through four innings with the NL Central leaders at 2-2.

And the Astros tied it impressive fashion off Mike Leake (7-8): back-to-back solo homers by left fielder Fernando Martinez, who sent a 409-foot shot into the upper deck in right field, and Dominguez.

“It was awesome …,” Dominguez said. “I don’t know how many at-bats I have, but it’s a relief to get it out of the way.”

Dominguez is hitting .375 in his brief time in the majors but knows that this year is merely a prelude to 2013, when the Astros try to retool their roster around the youngsters that now dominate the lineup.

Unfortunately, Abad (0-2) couldn’t keep the game tied in the fifth. Zack Cozart led off with a double to left and scored on a single by Chris Heisey, who took second when Jimmy Paredes bobbled the ball in right field.

Pitching execution key

Ryan Ludwick singled Heisey to third one out later, and Bruce brought both home with his three-run shot to right center.

From there, the game devolved into a tryout camp for the Astros’ battered bullpen, the reconstruction of which is a major project for DeFrancesco.

“One thing we have to do is execute pitches,” he said before the game. “The stuff is good. It’s command of each pitch that is giving us a problem. A fastball away doesn’t wind up a fastball away. It winds up over the plate and up, and good hitters know how to hurt a baseball.”